Patent US3935169A successfully refreshed from Google Patents.
US3935169A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing polyester powder
Assignee: Zeneca Inc
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Filing: 1974-06-28
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Granted: 1976-01-27
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Expires: 1994-06-28
Abstract
Abstract An improved method of preparing a polyester powder is disclosed wherein a polyester resin is dissolved in benzyl alcohol and the powder is subsequently precipitated from said solution by the use of a suitable diluent.This is a continuation of application Ser. No. 295,476, filed Oct. 2, 1972.
Inventors
- 👤 Robert Richard Reen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:40
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/14; C08J2367/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
52 words
A method of preparing a polyester powder from a synthetic polyester resin, selected from the group consisting of polyethylene terephthalate, polyethylene isophthalate, polyethylene orthophthalate, copolymers and mixtures thereof, said method comprising a. dissolving the polyester resin in benzyl alcohol; and b. precipitating the polyester powder by combining the solution with a diluent.
Claim 2
Independent Claim
52 words
A method of preparing a polyester powder from a synthetic polyester resin, selected from the group consisting of polyethylene terephthalate, polyethylene isophthalate, polyethylene orthophthalate, copolymers and mixtures thereof, said method comprising a. dissolving the polyester resin in benzyl alcohol; and b. precipitating the polyester powder by combining the solution with a diluent.
Claim 3
Dependent Claim
19 words
A method, as claimed in claim 1, wherein the polyester is dissovled by heating the solvent to about 180°C.
Claim 4
Dependent Claim
15 words
A method, as claimed in claim 1, wherein the polyester resin is a polyethylene terephthalate.
Claim 5
Dependent Claim
12 words
A method, as claimed in claim 1, wherein the diluent is xylene.
Claim 6
Dependent Claim
33 words
A method, as claimed in claim 1, wherein the solution is maintained at a temperature of from about 160°C. to about 205°C. for less than 30 minutes before being treated with the diluent.
Claim 7
Dependent Claim
20 words
A method, as claimed in claim 1, wherein the polyester powder is precipitated by adding the diluent to the solution.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-26 | 1979-07-28 | 1980-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-26 | 1983-07-28 | 1984-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-26 | 1987-07-28 | 1988-01-27 | $7700.00 | Window Closed / Lapsed |